Heat exchangers



Dec. 20, 1960 w. HRYNISZAK HEAT EXCHANGERS 4 Sheets-Sheet 1 Filed April16, 1957 Dec. 20, 1960 w. HRYNISZAK HEAT EXCHANGERS 4 Sheets-Sheet 3Filed April 16, 1957 W. HRYNISZAK HEAT EXCHANGE-RS v Dec. 20, 1960 4Sheets-Sheet 4 Filed April 16, 1957 United States Patent HEAT EXCHANGERSFiled Apr. 16, 1957, Ser. No. 653,095

8 Claims. (Cl. 257-245) This invention relates to heat exchangers of theplate type that is to say of the type which comprise a number of spacedsheets the spaces between the sheets forming flow channels for heatexchanging fluids which flow channels may be further subdivided bycorrugations.

The object of the present invention is to provide a heat exchanger ofthe above type which is easy to manufacture and assemble and suitablefor large scale production.

The invention consists in a plate type heat exchanger comprising aplurality of pairs of spaced sheets having side walls at the peripheraledges thereof forming flow channels of rectangular form, the spacesbetween the sheets being interrupted by corrugated inserts or bycorrugating the sheets themselves, the length of said corrugations beingsuch that spaces are formed between their ends and the side walls, andinlet and outlet openings being formed in said side walls said openingsin one wall being in staggered relationship to the openings in the otherwall the arrangement being that hot fluid channels alternate with coldfluid channels.

The invention further consists in a heat exchanger in accordance withclaims 2 to 11 below.

The invention also consists in plate type heat exchangers substantiallyas described below with reference to the diagrammatic drawings in which:

2,965,359 Patented Dec. 20, 1960 is only that of the sheets 4a, 4b whichshould be as thin as possible as heat transfer takes place between thosesheets in adjacent flow channels as will be more fully described later.To prevent burning through of the bent portions the channels can besupported in heat resistant material 5 as shown.

In Figure 3 a sheet 6 is bent so as to form a space of rectangular crosssection and in it are placed corrugated inserts 3a, 3b. As in the caseof the form shown in Figure 2 the parts of the sheet fulfilling thefunction of walls 2a, 2b in Figure 1 need protection from hot fluid by aheat resistant material 5. A plan view of the flow channel of Figure 3is shown in Figure 4. The staggered relationship of inlets 7a andoutlets 7b for the flow channel are shown and ducts 8 are provided inthe space between corrugated inserts 3a, 3b for the introduction of acleaning fluid if desired. The cleaning fluid may flow in eitherdirection through the channel passing through the inlet and outletopenings during a time when the supply of heat exchanging fluid to thechannel is cut off. Seals between the various openings are shown at 9,these seals abut.- ting against the side walls of the heat exchanger inwhich the inlets and outlets 7a and 7b are formed.

The parts of each flow channel can be made by rolling from strip and maybe assembled automatically with strips of brazing material 10 betweenthe various parts, the assembly then being heated to melt the brazingmaterial. After brazing the completed flow channel has the inlet andoutlet openings cut and then the requisite lengths cut oil for each heatexchanger.

Alternatively the assembled flow channel may be wound around a spool inmanner to be described later for instance in connection with Figures 8and 9 In all the flow channels shown in Figures 1-3 the corrugatedinserts act as secondary heat exchange sur- Figures 1-4 show variousforms of flow channel in which corrugated inserts form secondary heatexchange surfaces;

, Figures 5 to 7 show various forms of flow channel in which thecorrugated parts form a primary heat exchange surface; i

Figures 8 and 9 show a sectional view of heat exchanger in accordancewith one form of the invention;

Figures 10 and 11 illustrate details of a manufacturing process formaking a heat exchanger in accordance with the present invention.

Referring to Figure 1 a flow channel comprises two flat sheets 1a, 1bseparated by walls 2a, 2b. In the space formed between the walls 2a, 2band flat sheets 1a, 1b are two corrugated inserts 3a, 3b both identicalin shape and size and spaced apart from each other. The corrugations runat right angles to the walls 2a, 2b and, to enable heat exchanging fluidto enter the flow channel, inlets and outlets are cut in the said wallsas will be described more fully later with reference to Figure 4. It ispreferred that the inlets and outlets be in staggered relationship toone another to ensure an even distribution of fluid through the spacesformed by the corrugations.

Figure 2 shows a form of flow channel comprising two sheets 4a, 4bhaving their edges bent so as to abut one another thus forming a spacefor corrugated inserts 3a, 3b as before. Walls 2a, 2b are thus no longerrequired. Inlet and outlet openings are cut in the bent edges as before,after brazing the parts together. In this form the thickness of metal inthe path of hot fluid faces that is to say they increase the heattransfer area in the flow channel but each side of the corrugation issubjected to the same heat exchanging fluid.

In Figure 5 sheets 11, which are spaced from each other by walls 2a, 2bare themselves corrugated to avoid the use of separate corrugatedinserts. The corrugations are bounded on either side by flat marginalportions which are held between the walls 2a, 2b. As the corrugations ofadjacent sheets rest one on the other the corrugations are disposed sothat the corrugations of one sheet are at an angle to those of thesheets in contact therewith. As before the parts forming a flow channelcan be brazed together using strips of brazing foil 10.. The walls 2 canbe protected by insulating material 5.

In Figure 6 which may be regarded as illustrating the use of singleplates with their edges turned over the walls 2a, 2b of Figure 5 arereplaced by bending the edges of the sheets 11. In the form shown thecorrugations of the sheets 11 are interrupted between the flat marginalportions by a flat part 12 in which ducts 8; (see Figure 7) may beprovided to permit the introduction of cleaning fluid to flow in thechannels, if required, when the supply of heat exchanging fluid has beencut off.

The corrugations of each sheet 11 .in the case of Figure 5 are disposedso that the corrugations of adjacent sheets are at an angle to oneanother. The corrugations may all run in the same direction in one sheetor they may be disposed at an angle to each other on either side of fiatportion 12 as shown more clearly in the plan view of Figure 6 shown inFigure 7.

Inlets 7a and outlets 7b cut in walls 2 and the insulating material 5 inthe case of Figure 5 and in the insulating material 5 and end portionsof sheet 11 in the case of Figure 6 are staggered as shown. Seals 9separate the various openings.

In the form of Figures 5 and 6 the corrugated portions are part of sheet11 and hence form the dividing walls between flow channels; they thusform primary heat exchange surfaces as theyarein contact with hot fluidon one side and a cold fluid on the other.

Flow channels of the forms described in Figures l-3 or 5-6 can beassembled one on top of the other in the form of a column or stack,channels for'hot fluid alternating with channels for cold fluid or, asshown in Figures 8 and 9, wound in the form of a continuous strip arounda spool. In this way a plurality of inlets and outlets are formed on anannulus and the heat exchanger is in a convenient form for use with gasturbine plant where annular ducts are necessary. I

' Figure 8 is a section on the line 8'8 of Figure 9 and Figure 9 is asection on the line 9-'9 of Figure 8.

Radial grooves 13 are formed in the end walls of the heat exchanger asshown in Figure 9 and these grooves accommodate seals separating theinlets and outlets.

In the form illustrated in Figures 8 and 9 which may be regarded asshowing the use of pairs of flat tubes wound around a spool the openingsfor each flow channel have to be cut in a certain way. This is carriedout by assembling two flow channels completely and brazing themtogether, the two channels being in the form of long strips. One end ofeach strip is then fixed to a spool 14 as shown in Figure and the spoolcaused to rotate. The feeding of the two flow channels strips iscontrolled by rollers 15. Four cutters 16 are assembled on a tool 17which can be oscillated around an axis parallel to the strips so thatthe openings are cut simultaneously either onthe right side of theuppermost strips and on the left side of the lower strip or vice versadepending on the position of the cutters. The speed of the spool isincreased as the diameter of the heat exchanger assembly on the spoolincreases so that the openings are radially in line.

Figure 11' shows sections on the line 1111 of Figure 10 looking in thedirection of the arrows and shows the four cutters 16 in one cuttingposition. 7

In the complete heat exchanger shown in Figure 9 the inlets 7a are inradial alignment with each other and so are the outlets 7b, sectorscontaining inlets 7a alternating with sectors containing outlets 7b.

I claim:

1. A plate type heat exchanger comprising a plurality of pairs of spacedsheets having side walls at the peripheral edges thereof forming flowchannels of rectangular form, corrugated sheet material interrupting thespaces between the said spaced sheets, the length of the corrugationsthereof being such that spaces are formed between their ends and theside walls; and inlet and outlet openings being formed in said sidewalls said openings in one wall being in staggered relationing to theopenings in the other wall, the arrangement being that hot fluidchannels alternate with cold fluid channels.

2. A heat exchanger in accordance with claim 1 in which each pairofs'h'ee'ts are formed from continuous strips of metal and twosuchpairs, arranged one above the other, are wound around a spool theheat exchanging fluids flowing through the spaces between each pair ofsheets in a direction substantially parallel'to the axis of the spool. g

3. A heat exchanger in accordance with claim 2, in which the inlets andoutlets for hot fluid are respectively in radial alignment with eachother but displaced circumferentially respectively from respectivelyradially aligned outlets and inlets for cold fluid. ,7

4. A heat exchanger in accordance with claim 3, in which the end facesof the heat exchanger have radially extending grooves be'tween theradially aligned rows of inlets and outlets in which grooves seals aresituated to restrict leakage between the hot fluid path and the coldfluid path.

5'. A heat exchanger in accordance with claim 4, in whichon each side ofthe heat exchanger the hot'fluid is conducted to and from the heatexchanger bya' series of ducts interleaved with ductsconducting coldfluid to and from the heat exchanger.

6. A heat exchanger in accordance with claim 5 in which the side Wallsare formed by turning over the edges of each sheet.

7. A heat exchanger in accordance with claim 6, in which thecorrugations are formed in the sheetsth'etiiselves and the corrugationsof one sheet are disposed in angular relation to the corrugations ofadjacent sheets.

8. A heat exchanger in accordance with claim 7,. in which thecorrugations are interrupted intermediate their ends by a flat portionwhich flat portion has holes" therein to which a cleaning fluid can becommunicated.

References Cited in the file of this patent UNITED STATES PATENTS-799,621 Brewtnall- Sept. 12, 1 's 1,555,646 Emmet Sept. 29.19251,680,145 Forssblad Aug. 7; 1928

